The invention relates to vehicles comprising at least one glass pane and bodywork.
Under the effect of excitations generated by the engine and the contact of the tires with the carriageway, the windshield and the rear window of an automotive vehicle may become significant noise transmitters below a frequency of 800 Hz. Generally, when a windshield is vibrated by its mechanical supports or by an incident acoustic wave, it generates pressure waves that are transmitted through the passenger compartment to the detriment of the comfort of the passengers.
In order to improve the acoustic performance of automotive vehicles, the reduction of the vibrational level of these two panels, amongst other things, is the subject of many studies. Currently, two types of solutions are adopted.
The first consists in strengthening the body structure in order to decrease the propagation of the vibrational energy toward these panels. The effectiveness of this solution is limited by architectural constraints. This solution also results in an increase in the weight and cost of the body.
Another solution consists of a damping material of polyvinyl butyral (PVB) type. Indeed, windshields are known today that are made from this material, which was developed to shift the glass transition temperature toward 15° C. With this characteristic, the windshield has a high damping factor at room temperature. On the other hand, this solution has two drawbacks. On the one hand, its vibration-attenuating effect only becomes significant above 150 Hz, as below this frequency the deformation of the windshield prevents the PVB from working further. On the other hand, it represents a significant overcost (more than 10ε) relative to a conventional windshield.